With accelerating of stepping into an aging society throughout the world, various gerontal neurodegenerative diseases, such as mild cognitive impairment, senile dementia and the like, have become major risk factors that threaten human health in later life and decrease life quality of old people, which brings about serious economic burden and heavy psychological pressure to the society and families. Senile dementia can be divided into Alzheimer's disease (AD), vascular dementia, and a mixed dementia that the aforementioned two diseases coexist. Senile dementia is a primary degenerative brain disease occurring in or at the early stage of the geratic period, and is a persistent dysfunction of higher-order nervous activities. Clinically, it is manifested as worsening of cognitive and memory functions, progressive deterioration of daily life ability, as well as various symptoms such as neuropsychiatric, symptoms and behavior dysfunction. Senile dementia is a disease with relatively high incidence, and the data of the World Health Organzation shows that currently there are approximately 20 million older people suffering from senile dementia throughout the world, and it would expected that by 2020 there will be more than 30 million patients suffering from senile dementia throughout the world. Therefore, it is a research emphasis for medical workers of different countries throughout the world develop a drug for improving cognition impairment and treating senile dementia, which gains great attention from Chinese and western medical professions.
Currently, drugs used for treating senile dementia mainly include an acetylcholinesterase (AchE) inhibitor, an anti-immune-inflammation drug, a calcium ion antagonist, an antioxidant and the like. Such drugs approved by The Food and Drug Administration (FDA) (US) include donepezil, galanthamine, nimodipine, memantine hydrochloride and the like. These drugs can only temporarily relieve the deterioration of cognitive functions of the patients, but cannot suspend the progression of Furthermore, some of the aforementioned drugs have adverse effects such as serious liver and kidney toxicities, and some of the aformentioned drugs are too expensive to be afforded by the patients and family members thereof. Thus, it still needs to develop a new drug with a good therapeutic effect, little toxic and side effects and an appropriate price. Recently, specialists and scholars from China and abroad turn their attention to traditional Chinese medicines and natural medicines, and attempt m conduct a research on treatment of senile dementia. The modern traditional Chinese medicine (TCM) believes that, senile dementia is a common gerontal disease characterized by deficiency in origin and excess in superficiality, wherein the deficiency in origin is mainly caused by deficiency of the kidney essence, deficiency of marrow sea, and failure of lucid yang to rise; kidney deficiency is the root cause of senile dementia, and malnutrition of internal organs is closely related to the incidence of senile dementia. Therefore senile dementia is often treated by tonifying Kidney and strengthening essence.
As recorded in Encyclopedia of Chinese herbal medicine, Poria has effects of removing dampness and promoting diuresis, and calming the heart and strengthening the spleen, which can be used to treat edema and oliguria, dizziness and palpitation due to fluid retention, deficiency of the spleen and lack of appetite, loose stool or diarrhoea, malaise, and palpitation due to fear and insomnia. Acanthopanacis Senticosi Radix et Rhizoma seu Caulis (also known as “Acanthopanax”) has effects of invigorating qi and strengthening the spleen, and tonifying kidney and calming nerves, which is used treat Yang deficiency of both spleen and kidney, debilitation and hypodynamia, loss of appetite, waist and knee pain, insomnia and dreaminess. Epimedii Folium (also known as “Epimedium”) has effects of invigorating kidney and strengthening Yang; dispelling wind and eliminating dampness; strengthening muscles and bones, which is mainly used to treat impotence and spermatorrhea, deficient-cold-type infertility, frequent micturition and incontinence, kidney deficiency and cough with asthma, soreness and weakness of waist and knees, rheumatic arthralgia, hemiplegia, and insensitivity of the limbs. Anemarrhenae Rhizoma has effects of clearing away heat and purging pathogenic fire, nourishing Yin and moistening dryness, and quenching thirst and relieving restlessness, which may be used to treat warm febrile diseases; high fever and polydipsia; cough or asthma; cough caused by dryness; constipation; osteopyrexia and fever; dysphoria and insomnia; and diabetes and stranguria with turbid discharge.